The Mara once again takes control of Tegan's mind and compels her to
direct the TARDIS to Manussa, seat of its once-mighty empire.
Generations earlier, the Mara was driven off Manussa with the use of the
Great Crystal, a device which enhances its users' mental abilities. Now,
the Mara intends to use the Crystal to return to power. It is up to the
Doctor to unearth the terrible origins of the Mara, and seek out the one
man who can show him how to defeat the Mara in psychic combat.

Production

While Kinda, Christopher Bailey's first
Doctor Who serial, was wrapping up production in August 1981, he
and script editor Eric Saward were already beginning discussions about a
possible sequel for the next season. Working closely with Saward, Bailey
drafted an outline for a new story called Snakedance (sometimes
referred to as Snake Dance), which was commissioned on September
28th. Happy with the outcome, Saward requested the full scripts from
Bailey on November 9th.

Snakedance was soon pencilled in as the second story of Season
Twenty. However, it was placed first in the production order, as Serial
6D. Since it was a purely studio-bound story, it was not subject to the
vagaries of spring weather, and thus was a better candidate for
recording in April than the intended season opener, Arc Of Infinity, which would boast location
filming in Amsterdam. As with Kinda, Bailey
infused the names he chose for Snakedance with various hidden
meanings. Buddhist terms
again made an appearance, inspiring Manussa (“the human
realm”), Tanha (“craving”) and Dugdale (from
duggati, “unhappy existence”). Dojjen was an homage
to Dogen, a Zen master who lived in thirteenth-century Japan. Dugdale
had earlier been called Duchan (a platform used by Hebrew priests),
while Chela was named for a Hindi word meaning “religious
disciple”.

At Sarah Sutton's urging, it was agreed that Nyssa would
be portrayed as an increasingly mature woman prior to her departure

While Bailey was working on his scripts for Snakedance, it was
decided that Nyssa had been developed as far as possible, and Sarah
Sutton would bow out of Doctor Who midway through Season Twenty.
At Sutton's urging, it was agreed that Nyssa would be portrayed as an
increasingly mature young woman throughout the opening stories of the
season, and Bailey was asked to reflect this in his scripts. The regular
Doctor Who cast each received new contracts in February 1982.
Reflecting the plans for her character, Sutton was booked for twenty out
of twenty-six episodes on the 10th; however, the same day, Janet
Fielding was contracted for only eighteen episodes, suggesting that
there may have been some uncertainty about how much longer Tegan would
remain on the show. On the 11th, Peter Davison was booked for the
entirety of Season Twenty.

One change for the companions in the new year would be their costumes:
producer John Nathan-Turner had favoured a uniform look during the
nineteenth season, with Adric, Nyssa and Tegan all wearing essentially
the same clothes in every story. Now, both Nyssa and Tegan would be
allowed to change their outfits from adventure to adventure. Meanwhile,
Nathan-Turner himself was beginning to consider life after Doctor
Who. As Season Twenty neared production, Nathan-Turner began
developing a soap opera named Impact, which was planned to be an
updated version of the mid-Sixties BBC programme Compact.

The director assigned to Snakedance was Fiona Cumming, who had
worked on Castrovalva the previous year.
After making that story, Cumming had informed Nathan-Turner of her
willingness to return to Doctor Who, but indicated that she was
more interested in character-oriented scripts. Consequently,
Nathan-Turner thought that Cumming would be an ideal fit for
Snakedance. Amongst the cast Cumming assembled was Brian Miller,
playing the showman Dugdale; Miller was the husband of Elisabeth Sladen,
who played companion Sarah Jane Smith in the mid-Seventies.

Two weeks prior to the start of production on Snakedance, on
March 18th, series star Peter Davison was asked to film what he believed
to be a promotional trailer for Australian television. In fact, this was
a ruse concocted by Nathan-Turner. In reality, when Davison arrived on
location, he was surprised to find Matthew Waterhouse (Adric), Sarah
Sutton and Janet Fielding already there in full costume. Davison was
even more surprised to discover that they were accompanied by Eamonn
Andrews, and that he was the subject of Andrews' popular programme
This Is Your Life. The occasion marked the second time that a
Doctor Who star had been featured on This Is Your Life,
the other being Jon Pertwee in 1971. Davison's episode aired a week
later, on March 25th.

For timing reasons, a closing scene in which the Doctor
reassures Tegan about the Mara was held over to Mawdryn Undead

Work on Snakedance inaugurated Doctor Who's twentieth
recording block, beginning with the scenes set in the Manussan hills,
which were filmed at the Ealing Television Film Studios on March 31st.
Recording for Snakedance took place in BBC Television Centre
Studio 6, starting with a three-day session from April 12th to 14th.
The first day dealt with scenes in the Manussan marketplace, while the
second concentrated on material in and around Ambril's office. The 14th
entailed the use of several venues, including the Hall of Mirrors, the
Doctor's cell, and various corridors. Designer Jan Spoczynski had wanted
to use an outside firm to build the sets for Snakedance, but
permission was withheld until almost the very last minute. Consequently,
the sets had to be constructed very quickly, and Spoczynski was
disappointed with the results.

The second studio block spanned April 26th to 28th. All three days
involved sequences in the cave, while the 26th also dealt with material
in Lon and Tanha's chambers, and scenes inside the TARDIS were taped on
the final day. In post-production, it was discovered that part four
was badly overrunning, forcing Cumming to restructure much of the
episode. One major sequence -- in which the Doctor reassures Tegan
that she no longer has to worry about the Mara -- was dropped
altogether, with the production team electing to hold it over to start
the next serial, Mawdryn Undead,
instead.

Saward was happy with Snakedance and was eager to work with
Bailey again. Late in 1982, Bailey began developing a story called
“May Time” (later renamed “Manpower”), although
this was eventually abandoned. The next year, Bailey started working on
an adventure for the Sixth Doctor entitled “The Children Of
Seth” (which Bailey recalls as having been a revised version of
“Manwatch”). At this point, however, Bailey became
disillusioned with the lack of collaboration in television, and he
decided to leave the industry. He subsequently helped found the
successful community arts program Same Sky.